Electromagnetic brake



May 17 1927.

V. MORSE ELECTROMAGNETI G BRAKE Filed Auz. "1, 1924 2 Sheets-Sheet 1 XNVENTDR WW4 H. V. MURSE ELECTROMAG May 1? 1927 NETIC BRAKE Filed Aug. '7, .1924 2 Sheets-$heet 2 iNVENTOR Patented May 17, 1927..

Parent OFFICE.

ROBERT V. "MORSE, F ITHALCA, NEW YORK.

mucrnomsnnarrc Bnsnnl Application filed August 2, 1924-.

This invention relates to brakes, and has for its purpose the substitution of electromagnetic drag for frictionaldrag, particularly when operating at high speeds, while at the same time permitting frictional brakin when necessary; Another object as applied to vehicles is to provide a brake which will automatically tend to release when a wheel ceases to rotate. so as to reduce the danger of skidding. Gther objects, relating to ease of application, simplicity of construction, and permanence of adjustment will besome apparent as the description proceeds.

Referring now to the drawing, Fig. 1 is a cross-section showing by way or illustration a form of the brake as applied to the wheel of a vehicle; Fig. 2 shows a modification,

In the example shown in Fig. 1, the wheel 1 is mounted to rotate on the axle 2. The frame 3 is fixed to the axle 2 so as not to rotate thereon, and carries the magnetic field structure 4-. The armature 5 is bolted to the wheel disk 1, and the action of-the'brake is to. impose a drag or counter-torque on the rotation of the wheel 1, as will be described.

The field structure l may" be moved axially by any suitable means, such as a lever, cam, wedge, or screw; in the example shown in Fig. 1 the frame 3 and field structure i are provided with screw threads 6, so that when the field structure t is turned by means of the arm I it will be moved axially. When the field structure 4.- is thus moved to the right in the drawing the brushes 8, 9, and

J are brought in contact with the armature 5. This completes an electric circuit which may be described as beginning at the brushes 8, thence outward thru the field coil 11 to. the terminals 12,at which the current divides, part of it going to the brushes 9 and part to the brushes 10. From the brushes Sand 10 the circuit passes thru the armature 5 back to the. point of begining at the brushes 8. ,The field coil 11 is preferably annular in shape, extending around the armature, and may either be composed of complete coils, or may be built up of inclined leads between the brushes 8 and terminals 12. each lead extending a fraction of a turn, which serves the same purpose. This annular type of excitation creates .a pair of homopolar fields, each'of constant polarity entirelyaround the armature, one of the homopolar fields lying between the brushes 8 and the brushes 9, and the other lying serial l'lo. 2 30,7521

between the brushes Sand the brushes 10. These two homopolar fields are of opposite po arity, so that when the armature 5 is rotated the generated currents will flow in opposite directions across them, as forexample from the brushes 9 and 10 inward to the brushes 8. In accordance with the laws of electricity'the direction of current flow is such as to oppose the rotation of the armature 5,- and thus it exerts a braking efiect on the wheel 1. A low resistance in the circuit which has been described facilitates a' heavy'fiow of current. The current flow and brakingeilect can be varied at any given speedv by varying the field strength. which can be done in a self contained unit such-as described by varying the air gap, as by makmg the air gap radial or at least tapered, so

that asthe field structure 4; is moved axially very powerful braking efiect, particularly as it is reinforced by magnetic action, and is chiefly useiul' ioi coming to a dead stop, whereas the electro-dynamic braking previously described is most, usefulin regulating the rolling speed. Instead of using the field structure a itself as a brake shoe, as has been-described, any suitable form of separate brake shoe may be attached thereto if desired, and any suitable brake lining may be employed, as at 16 in Fig. 2.

The modification shown 'in Fig. 2* while in general similar in principle to Fig. 1 as previously described, employs but one armature circuit between the brushes 8 and 9 instead of two circuits betweenbrush 8 and 9 and the brush 8 and brush 10 as used in Fig". 1. Also in place of the screw thread 6 a mechanical equivalent cam orcam surface 6 is illustrated;

. The electrical action operates lowing ding. It will be understood that the ordinary friction type'of automobile brakes are in the 01 usceiiy equaiizci so fer esti means being; brake baiicis is comterne l, member in ere applied and one 07? are strike slippery piece of brake, the combination of e rotatfric'iion beiweee he tire and the read is I 431' to be bra-iced, dynamowiecfric chain the friction Hie brake been A v wine having brushes arranged so kiwi whee: Wiii preniptiy cease to rotate a. 'iiizmiqe ix no?) flcfii'flg' the circuit cf sic em. Thus ii iimiizmg iii viii be app! 21!,

brake pre ame sillfiiliiiiii i710 pressure en iiiie res? e? the wakes iii!) will remain locked and SIiddiiig iilme. in the electrical Lype of has been described the braking eciien maiiy not merely 2: function of oe sure iOlli', eisc cf the rotei'irc spew z'io-eicctric machine is broken a, Li

so shat ii; is? opcrme 2w Juicbrcike, furtier zippiice e eppiying; means serving to ep of the magnetic ciro-eieetric machine so :1: king eii'ecf.

diminish (nit 'Wheei, since the retafzieii of the W iieci eir 3. :he ccmbinafio' o? emies "he electric currents "ii if; airing the ing me crzzkeoi, a .imo-e magnetic i at 'ii'o action. If machine errsngeci to operate 2m ciccircthe i one 0" ciyrizui'iic brake, mic mez-ins for viu: ing the L e2 3. gap of said dynamo-electric machine be i I cf'iei movement relative 'tesaid rota: v if member so to increasetiie magnetic ectien on the other wiieeic. Thus: he yiiamc-eiectrie machine as the brake raking force in effect a Amii'eci; Eli nppiiefl.

1 of et he bra "n brake, the comiaimiion of an i ire-dynamic machine confipis "11d -c'ture, en armature, a circuit the saici machine may ope w. dynamic brake, a brake ranged so as to first eiose sai' further appiicatien to 7 i reieiwe to 1 e field with a surfer:v ec r so 5:0 create L in? effect" 1511 a brake, the coinbiimtiezi 0. =1 eiec iro-ciynamic machine comprising a fie true en arme mre, a CHCIUi) arranged so cizros i L! w L i met said machine may operaie as an :1 dynamic brake, and a brake app m arranged so as to first close on Iuriher epphcetlen cilininisil the of the mngne'sic circuit cf flue erecti e ERIC machine SC" 5.15 )L'O IHCTGi-LSEE e met and finally to bring e surface Y 3 relative re the field structure into mntect er e znuiaipo r with a surface ilxed. relative to the armature empieyeci so a 1Z0 create an additional frictional brakhcmopoier cype; the i aid Junie imp; effect. either inside air-outside the armature or the 6. In a brake, the combination of :1 eir gap may mereiy i and he frichomopoinr fieki structure, an an eture,

reeiei tiori sur aces are cepai'iie of. nenii oki veriabrushes normally out of contact wiih the ing i'nemoer JR be iicziked, friction e aciapied to operate on eaiei member", inechemical means for apply seifi friciiien brake, magnetic I! fer eugmeniing '5' force of mechanical means when cioii Wiii be apparent to those skiilcri in armature when the brake is not applied, 0 the era. Tee "mr'ticiiiar arrangemeni; shown series field circuit between the brushes, and is given merely by way of iiiufirafiion, and a brake applying means arranged to produce the esseriiiai fczi'ivuree and conibiimiiens an movement between {he em strum consfitifie the invention are embodinre and ihe armature so as to first brine; in the foiiowing ciein'is: the brushes into contact- With the. m'i'nai'nre 1. In e brake, the cembineiion of e roietiiien diinin eh the air gap between the iieid 1 structure nru'i (he armrifure the brake .rcrther appiied, and finally 0 bring 'fi'iciienai eeni'ecibetween :i

I ire '50 the iieici structure an ixec'. relative 5c the armature, 

